He wanted this gyroscope to keep a platform perfectly horizontal, no matter how rough the sea was.
His eyebrows were two straight lines across his perfectly horizontal brow ridge.
If an airplane flys perfectly horizontal, it should radiate in the perfect middle.
Use the level to make sure this first row is perfectly horizontal; if it is not, then the entire job will be out of square.
He sat down anyway, on a big log that sat so perfectly horizontal to the water it might have been arranged there.
If it finds one it rotates the photograph slightly to make the line perfectly horizontal.
A very accurate thrust, gentlemen, the knife came in perfectly horizontal so it didn't jam on the ribs.
Note that a perfectly horizontal surface is not needed.
It rose, staying perfectly horizontal because she wanted it that way.
Assume the car takes off in a perfectly horizontal direction.
